Control protection in automatic washing machines



IC WASHING MACHINES May 22, 1962 H. J. JONES CONTRQL PROTECTION INAUTOMA Filed Sept. 16. 1959 FIG. i

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FIG. 2

INVENI OR HERBERT J. JONES ATTORNEY Patented May 22, 1962 3,035,597CQNTROL PROTECTION IN AUTOMATIC WASHING MACHINES Herbert J. Jones, 71117th St., Boulder, Colo. Filed Sept. 16, 1959, Ser. No. 840,787 1 Claim.(Cl. 137-171) This invention relates to an improved apparatus forprotecting the hydrostatic control tube connecting the water levelcontrol diaphragm to the low pressure region of the centrifugaldischarge pump as used on automatic washing machines from soap bubblesbeing drawn back into the hydrostatic control tube. The soapsuds carriedback by pressure equalization, are carried far up in the verticalsection of the hydrostatic control tubewhere they in time settle outinto segments of water alternated by segments of air and due to thecapillary action of the small size of the hydrostatic control tube andthe absence of pressure behind the entrapped segments of water, allowsthem to remain. The entrapped segments of water in the vertical sectionof the hydrostatic control tube gives an adverse efiect on the waterlevel control diaphragm by imposing added resistance to be overcome bythe static column of water in washtub in lifting or moving theseentrapped segments of water.

Referring to the E. O. Morton Patent No. 2,592,314, you will note thatthe hydrostatic control tube is attached to the centrifugal dischargepump at a point adjacent to the center of the impeller which is a lowpressure region. The low pressure developed by the centrifugal dischargepump at the point of attachment of the hydrostatic control tube causesthe hydrostatic control tube to be under partial vacuum during thepumping cycle when the vitiated water is being removed from the tub. Atthe end of the pumping cycle, equalization of pressures takes place andair rushes into the low pressure region of the discharge pump by the wayof the washtub and discharge pump and carrying with it water andsoapsuds far back into the hydrostatic control tube. The object of thisinvention is to provide means to prevent soapsuds from being drawn backinto the hydrostatic control tube. To consummate the object of thisinvention, I have assembled a combination of several parts forming anapparatus which I will hereafter designate as a bubble trap. A drawingis hereby submitted showing the bubble trap and how it is to be used inconjunction with a washtub, centrifugal discharge pump and pressureresponsive spring return water level control diaphragm and being similarto that used in the E. O. Morton Patent 2,592,314.

FIG. 1 shows the bubble trap.

FIG. 2 shows the bubble trap in combination with a washing machineapparatus.

The bubble trap comprises a tank 5 which is provided with an opening 5a.This opening is accomplished by the insertion of a copper tube into thetank 5 which extends downward into tank 5 so as to leave a space at thetop of tank 5 for air and a space at the bottom of tank 5 for water tobe stored. A section of the copper tubing forming opening 5a extends outof tank 5 and forms a place of attachment for a plastic tube andcommunicates with the interior of tank 5. Opening 5b is accomplished byinserting a copper tube into tank 5 and extending it downward near thebottom of tank 5 so that it can communicate with the stored water intank 5 and the end of the copper tube will always be submerged in thewater stored in tank 5. A short portion is left projecting out of thetop of tank 5 so that a plastic tube can be connected to and communicatewith the water stored in tank 5. Opening 5c is accomplished by insertinga copper tube into the top of tank 5 and is even with the underside ofthe top of tank 5. A portion of the copper tubing projects out of tank 5so as to provide a place to attach a plastic tube thereto. At the pointof insertion of 5a, 5b, and 50 into tank, which is of copper, theoutside of the copper tubes are soldered to the tank 5 and made secureagainst leaks.

The operation of the bubble trap depends upon a stand-pipe 7 which isattached to the opening 50 and comprises a plastic tube and extends toan altitude well above the Water source which the bubble trap is incommunication with and is a part of the bubble trap. Standpipe 7 cancommunicate freely with the inside of tank 5 and the other end of whichextends to a higher elevation is left open to atmosphere and cancommunicate freely with the top of washtube 2. Realizing that thisbubble trap can assume many shapes and sizes as well as being made ofmany suitable materials, the applicant chooses to be free to select anymaterials for construction of the bubble trap and determine the shapeand size.

Referring to FIG. 2, I will explain the manner of incorporating thebubble trap 5 with the automatic controls of the washing machine and howit operates to protect the hydrostatic control tubes 4 and 6 frominterference by soapsuds. The bubble trap is interposed between thecentrifugal pump 3 and the pressure responsive water level controldiaphragm 8. The bubble trap is connected and communicates with pump 3by a short section of plastic tube 4 connected to and communicates withbubble trap 5 through its opening 5a. The water level control diaphragm8 is connected to the bubble trap 5 by being connected to the opening 5bby the hydro static compression tube 6 and can communicate freely withthe entrapped Water retained in the bubble trap 5. A stand-pipe tube 7is connected to the remaining opening 50 and is of variable length andmust extend to a higher altitude than the water which the bubble trap 5is communicating with. Stand-pipe 7 is open at its elevated end toatmosphere and may be connected to and communicate with the top of thewashtub 2. The position occupied by the bubble trap in relation to thecentrifugal discharge pump 3 is shown in FIG. 2 wherein it should be ofthe same elevation.

The operation of the bubble trap will be explained by assuming that thewashtub 2 is filled with its normal load of vitiated water and the cyclefor discharging the vitiated water is to begin. At this time Wateroccupies the space in the centrifugal discharge pump 3, the connectinghydrostatic tube 4, all the space inside of the bubble trap 5, the spaceinside stand-pipe 7 to an altitude of that of the wash water in washtub2, and the space in hydrostatic tube 6 which is not occupied bycompressed air. The compressed air in the hydrostatic tube 6 which isproduced by the weight of the column of water with which the tube iscommunicating is impressed on the water level control diaphragm causingit to move to a position enabling the master timer (not shown) to startthe discharge pump 3 and the cycle for discharging the vitiated waterfrom the washtub begins. All of the water occupying the spaces in thehydrostatic tube 4, the standpipe 7, the hydrostatic compression tube 6and the space in the bubble trap above the bubble trap opening 5a isreturned to the centrifugal discharge pump 3. At this time all lowpressure regions developed by the pumping action of the discharge pump 3are vented to atmosphere by the way of the stand-pipe 7 which is indirect communication with atmosphere. The results that my inventionaccomplishes at this time are venting the hydrostatic control tubes 4and 6, the low pressure region in the centrifugal discharge pump 3 andthe isolation of the compression chamber of the hydrostatic tube 6. Byproviding means for venting the low pressure regions between thedischarge pump and the control tube 6,

soapsuds are prevented from being drawn back into the hydrostaticcontrol tube 6. By providing a quantity of stored water in tank 5 andreturning this water back to pump 3, soapsuds are washed back to pump 3.By venting to atmosphere through stand-pipe 7, the compression chamberportion of the hydrostatic control tube 6 is isolated from theinfluences of low pressure. By retaining a quantity of Water in thebubble trap and submerging the compression chamber portion of thehydrostatic control tube 6 in this water, a blocking action can besecured against the entry of soapsuds in the compression chamber portionof the hydrostatic control tube 6. When all pressure is released on thebubble trap, the water level control diaphragm returns to its originalposition by spring loaded, and the next cycle begins. In the next cyclethat follows, filling the washtub with wash water, all of the space inthe bubble trap, the hydrostatic control tube 4, the stand-pipe 7, andthe space not occupied by air in the hydrostatic tube 6 is again filledwith Water. The air from these spaces is expelled to atmosphere throughstand-pipe 7. As the end of the hydrostatic control tube 6 which servesas the compression chamber and communicates with the bubble trap throughopening 5b is always submerged in water, a blocking action is effectedagainst soapsuds entering this tube 6 and any soapsuds entering thebubble trap 8 during the filling of the washtub with water is expelled.

What I claim is:

In a cleaning apparatus; in combination: a Washtub of a washing machinefor containing cleaning water, an inlet to the tub, an outlet from thebottom of the tub, a centrifugal pump in the outlet for removing liquidfrom the tub, means comprising pressure responsive diaphragm means forcontrolling the washing cycle, a compressed air tube connected to thepressure responsive diaphragm means for controlling the diaphragm, abubble trap comprising a housing having a chamber, a vent pipecommunicating at one end with the upper end of the chamber and at theother end with atmosphere at a point above the highest liquid level inthe tub, conduit means communicating a low pressure region of the pumpadjacent the center of the impeller thereof with a region intermediatethe upper and lower ends of said chamber, means connecting saidcompressed air tube with the lower end of said chamber so that a liquidseal is always provided for said compressed air tube.

Oakley June 21, 1898 Morton Apr. 8, 1952

